# -*- coding: utf-8 -*-
#
#  Tumgreyspf
#  Copyright © 2004-2005, Sean Reifschneider, tummy.com, ltd.
#
#  pypolicyd-spf changes
#  Copyright © 2007-12 Scott Kitterman <scott@kitterman.com>
'''
   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
'''

import syslog
import os
import sys
import re
import stat


#  default values
defaultConfigData = {
        'debugLevel' : 5,
        'HELO_reject' : 'SPF_Not_Pass',
        'Mail_From_reject' : 'Fail',
        'PermError_reject' : 'False',
        'TempError_Defer'  : 'False',
        'skip_addresses' : '127.0.0.0/8,::ffff:127.0.0.0/104,::1',
        'defaultSeedOnly' : 1,
        'Header_Type' : 'SPF',
        'Lookup_Time' : 20,
        'Void_Limit' : 2
        }


#################################
class ConfigException(Exception):
    '''Exception raised when there's a configuration file error.'''
    pass


####################################################################
def _processConfigFile(filename = None, config = None, useSyslog = 1,
        useStderr = 0):
    '''Load the specified config file, exit and log errors if it fails,
    otherwise return a config dictionary.'''

    import policydspfsupp
    if config == None: config = policydspfsupp.defaultConfigData
    if filename != None:
        try:
            _readConfigFile(filename, config)
        except Exception as e:
            if useSyslog:
                syslog.syslog(e.args[0])
            if useStderr:
                sys.stderr.write('%s\n' % e.args[0])
            sys.exit(1)
    return(config)


#################
class ExceptHook:
   def __init__(self, useSyslog = 1, useStderr = 0):
      self.useSyslog = useSyslog
      self.useStderr = useStderr
   
   def __call__(self, etype, evalue, etb):
      import traceback
      tb = traceback.format_exception(*(etype, evalue, etb))
      tb = list([a.rstrip('\n') for a in tb])
      tb = '\n'.join([c for c in tb])
      for line in tb.split('\n'):
         if self.useSyslog:
            syslog.syslog(line)
         if self.useStderr:
            sys.stderr.write(line + '\n')


####################
def _setExceptHook():
    sys.excepthook = ExceptHook(useSyslog = 1, useStderr = 1)


###############################################################
commentRx = re.compile(r'^(.*)#.*$')
def _readConfigFile(path, configData = None, configGlobal = {}):
    '''Reads a configuration file from the specified path, merging it
    with the configuration data specified in configData.  Returns a
    dictionary of name/value pairs based on configData and the values
    read from path.'''

    debugLevel = configGlobal.get('debugLevel', 0)
    if debugLevel >= 5: syslog.syslog('readConfigFile: Loading "%s"' % path)
    if configData == None: configData = {}
    nameConversion = {
            'debugLevel' : int,
            'HELO_reject' : str,
            'Mail_From_reject' : str,
            'PermError_reject' : str,
            'TempError_Defer' : str,
            'Mail_From_pass_restriction' : str,
            'HELO_pass_restriction' : str,
            'Prospective' : str,
            'Whitelist' : str,
            'skip_addresses': str,
            'Domain_Whitelist' : str,
            'Domain_Whitelist_PTR': str,
            'No_Mail': str,
            'Reject_Not_Pass_Domains' : str,
            'Per_User' : str,
            'defaultSeedOnly' : int,
            'Header_Type' : str,
            'Authserv_Id' : str,
            'Lookup_Time' : int,
            'Void_Limit'  : int
            }

    #  check to see if it's a file
    try:
        mode = os.stat(path)[0]
    except OSError as e:
        syslog.syslog(syslog.LOG_ERR,'ERROR stating "%s": %s' % ( path, e.strerror ))
        return(configData)
    if not stat.S_ISREG(mode):
        syslog.syslog(syslog.LOG_ERR,'ERROR: is not a file: "%s", mode=%s' % ( path, oct(mode) ))
        return(configData)

    #  load file
    fp = open(path, 'r')
    while 1:
        line = fp.readline()
        if not line: break

        #  parse line
        line = (line.split('#', 1)[0]).strip()
        if not line: continue
        data = [q.strip() for q in line.split('=')]
        if len(data) != 2:
            if len(data) == 1:
                if debugLevel >= 1:
                    syslog.syslog('Configuration item "%s" not defined in file "%s"'
                        % ( line, path ))
            else:
                syslog.syslog('ERROR parsing line "%s" from file "%s"'
                    % ( line, path ))
            continue
        name, value = data

        #  check validity of name
        conversion = nameConversion.get(name)
        if conversion == None:
            syslog.syslog('ERROR: Unknown name "%s" in file "%s"' % ( name, path ))
            continue

        if debugLevel >= 5: syslog.syslog('readConfigFile: Found entry "%s=%s"'
                % ( name, value ))
        configData[name] = conversion(value)
    fp.close()
    
    return(configData)

